diff options
Diffstat (limited to 'sysif.c')
| -rw-r--r-- | sysif.c | 47 |
1 files changed, 41 insertions, 6 deletions
@@ -902,7 +902,7 @@ void repress_privilege(void) orig_euid = geteuid(); if (real_uid != orig_euid) - seteuid(getuid()); + seteuid(real_uid); else is_setuid = 0; @@ -911,8 +911,44 @@ void repress_privilege(void) void drop_privilege(void) { - if (repress_called != RC_MAGIC || (is_setuid && setuid(getuid()) != 0)) + /* Bug: repress_privilege wasn't called. */ + if (repress_called != RC_MAGIC) abort(); + + if (!is_setuid) + return; + +#if HAVE_SETRESUID + { + if (setresuid(real_uid, real_uid, real_uid) != 0) + abort(); + return; + } +#else + { + /* First, try to regain as much privilege as possible. + * On some platforms, setuid requires the caller to be effective + * root in order to change the saved user ID. We don't want this + * call to fail just because we weren't effective root, even though + * we have the privilege to be effective root! + */ + (void) setuid(0); + + if (setuid(real_uid) == 0) { + if (orig_euid == 0) + return; + /* If we can re-gain the previous + * effective ID, then setuid(getuid()) + * didn't actually work; it didn't + * set the saved ID. + */ + if (real_uid != 0 && seteuid(orig_euid) == 0) + abort(); + } + + abort(); + } +#endif } void simulate_setuid(val open_script) @@ -934,14 +970,13 @@ void simulate_setuid(val open_script) abort(); if ((stb.st_mode & (S_ISUID | S_IXUSR)) == (S_ISUID | S_IXUSR)) { - seteuid(stb.st_uid); - return; + if (seteuid(stb.st_uid) == 0) + return; } } } - if (is_setuid) - setuid(real_uid); + drop_privilege(); } #endif |